Preserving the structural and functional integrity of biomolecules during isolation or purification from a biological sample is essential for various downstream applications including analyte detection, sensing, forensic, diagnostic or therapeutic applications, and the like. The extraction and stabilization of proteins, peptides or amino acids derived from a biological sample are sensitive to a number of environmental factors including, but are not limited to, solution pH, temperature, and the ubiquitous presence of various proteases. Consequently, proteins or peptides in solution states are typically stored under refrigeration (e.g. 4° C., −20° C., or −80° C.) to prevent hydrolysis and enzymatic degradation and to preserve the integrity of protein structure or function.
Dry-state technologies claiming successful collection and preservation of proteins or peptides in dry formats typically require protein to be “pre-purified” and “concentrated” from a sample prior to storage. Other dry-state technologies for the preservation of proteins in dry formats require additional drying facilities (e.g. forced air flow, lyophilization). These methods are therefore not conducive to direct collection and stabilization of proteins or peptides from a sample (e.g., a biological sample) without additional and significant processing steps.
Proteins or peptides are prone to denaturation and consequently tend to lose biological activity or epitope recognition during storage. Proteins that are targets of different analytical tests, such as biomarkers or biological therapeutic drugs, may be present in low quantities in unpurified states. Thus, methods for maximizing the recovery of protein analytes of interest are highly desirable. Degradation of protein or peptide may be slowed or prevented using chemical additives that, for example, inhibit protease activity. However, the presence of chemical additives may affect down-stream analytical techniques including mass spectroscopy and immunoassays.
Untreated cellulose paper substrates, such as, 903 or 31ETF papers (Whatman™, GE Healthcare) or Grade 226 paper (Ahlstrom, PerkinElmer) are used widely for preservation of enzymes, antibodies, proteins, peptides, and amino acids in dried blood spots for analytical purposes such as neonatal testing. However, the recovery of analytes from untreated cellulose substrates and subsequent biological activity of said analytes, particularly proteins that are prone to degradation, are often not sufficient. Dried specimens, such as dried blood spot samples used in neonatal testing, are generally stored under refrigeration to maintain analyte stability. Analytes which can be eluted inefficiently from dried blood spots may be interpreted in the art as unstable targets due to poor functional recovery. Supplementing different chemical fillers to stabilize proteins has been reported in the art, however the fillers have limited ability to recover and stabilize sensitive proteins.
Accordingly, compositions and methods which enable collection and extraction of biomolecules including proteins, peptides or amino acids from a biological sample, and then stabilize the biomolecules under a dry-state and ambient conditions without pre-purification, and elute the biomolecules in a substantially intact form thereafter for further analysis are highly desirable.